Conical strip shaping apparatus



Feb- 22, 1966 I L. s. LlNDE ROTH, JR., ETAL 3,235,033

GONIGAL STRIP SHAPING APPARATUS 3 Sheets-Sheet 1 Filed Feb. 6, 1963 m 1 W R,

fm Q a? i T Feb. 22, 1966 s. LINDEJROTH, JR., ETAL 3,236,083

CONIGAL STRIP SHAPING APPARATUS Filed Feb. 6, 1963 3 Sheets-Sheet 2 V @Cul21"\sE.MmEP

1956 1.. s. LINDERQTH, JR., ETAL 3,235,033

CONICAL STRIP SHAPING APPARATUS 3 Sheets-Sheet 3 Filed Feb. 6. 1963 J. M m .mw w 9mm T E WW L @M W United States Patent 3,236,083 CONIQAL STRIP SHAPING APPARATUS Lambert S. Linderoth, Jr., Battle Creek, Mich, and

Curtis E. Maier, Western Springs, 111., assignors to (Iontinental Can Company, Inc., New York, N.Y., a corporation of New York Filed Feb. 6, 1963, Ser. No. 256,642 2 Claims. (Cl. 72176) This invention relates in general to new and useful improvements in the art of producing continuous lengths of tubing from coils of thin metal. In a principal aspect it provides a commercially feasible apparatus for guiding a longitudinally extending thin strip by its edge portions into tubular shape for subsequent joining together. Strip edge joining may be accomplished by either hot forging or fusion welding; by the application of a high energy source for heating the two edge portions to be joined, coupled by resistance, induction, capacitance, reactance, and by an electric arc. Joining may also be accomplished by cold pressure, or by soldering. Further, by the use of this apparatus, joining together of the strip edges is accomplished without abrading, scratching or scufling either exterior or interior surfaces which otherwise renders the tubing unsuited to the requirements of container bodies to be made therefrom.

Heretofore, thin walled metal containers, such as are used for packaging comestibles, industrial products, pharmaceuticals, etc., have been produced by several well ordered steps from thin metal sheets of the proper gauge, having a plain exterior surface, or lithographed printing, decorative or protective coating applied to the exterior surface thereof, slit to length and width suitable for a single container body. This slit container body was then formed into cylindrical or other suitable shape as required, by bringing the edges into opposing relationship either overlapping or in a lock-and-lap hooked engagement. While thus confined in tubular configuration, the opposing related edges were soldered. Ends can be attached to the container body by any one of a variety of methods but preferably by flanging the container body and applying bottom and top closure ends by the rolling engagement into a conventional double seamed structure of hooks on the container bodies and the container ends.

The constantly increasing costs of material and labor over the years has been a continuous problem to the metal container industry which they have succeeded substantially in offsetting by producing better performing and cheaper metal containers for the perishable food canning industry, as well as for packaging industrial products, pharmaceuticals, cosmetics, etc. Numerous and important technological developments in this industry include the production of steel, tin plated steel ,and aluminum alloys in coil form instead of sheet form. These materials are available in thinner gauges and have stronger properties. Their electro-deposited tin coatings are as little as A as thick as when tin coatings were applied by hot dipping. Furthermore, electro-deposited tin coatings may now be deposited with of tin coating per base box on one side or on both sides, or up to 1# of tin coating per base box on the reverse side. Additionally, container bodies and end seams are now stronger and cheaper as a result of using tin-lead solders containing 2% tin 3,236,083 Patented Feb. 22, 1966 instead of solders containing 30%, 50% tin and even 100% tin, that were formerly used by the metal container manufacturing industry. Also, a great number of protective coatings have been developed for the inside of containers made from this cheaper electrotinned steel plate. This permits the supply to canning customers of customized metal containers providing better keeping qualities, the least possible attack of the container by the product, and the longest possible packed container life, thus permitting an adequate safety factor over the distribution and storage life required for the products packed therein. Thus of the meta-l containers made in 1961 were inside enameled whereas only 25% were inside enameled in 1937. Containers with outside protective or decorative coatings and lithography have also increased from less than 10% in 1937 to about 50% in 1961.

Despite more fully automating and substantially increasing the speeds of one-at-a-time metal container body manufacturing equipment over the years, it has only been possible to attain by the process of one-at-a-time container body forming and container body side seam soldering described above manufacturing speeds of about 400 to 500 containers per minute.

Continuous tube welding accomplished by joining together the opposing edges of the continuous elongated strip of approximately the container body circumference width in a continuous manner is a new and considerably faster and cheaper method of manufacturing container bodies.

Tube forming equipment is well known in the prior art and is commercially available from various suppliers. This equipment has been employed for forming and for bringing the opposing edges of heavy gauge strip into either overlapping or butting relationship, and has been advantageously employed in the manufacture of welded pipe and heavy gauge tubing.

characteristically this equipment employs a multiplicity of male and female rollers. Each pair of these rollers is confined in a heavy housing and the pairs of rollers are disposed along the path of the strip to gradually form the heavy gauge metal permanently and transversely until the edges of the longitudinal strip are brought into butting relationship, or contacting relationship, so as to configure the strip into the desired tubular shaped form. If the oppositely disposed edges of the strip are brought into butting relationship too rapidly, then the edges of the strip are stretched longitudinally more than the center portion and the resulting longitudinally welded pipe is wavy. Further, permanent crimps and paneling of the resulting strip are produced and often persist in the tubular pipe.

The equipment presently employed for forming heavy gauge metal strip into tubular form operates at relatively slow speeds. It is ponderous. It requires a multiplicity of expensive forming mills and forming tools for each diameter pipe. This already expensive multiplicity of equipment becomes still more costly because each thickness of pipe, even though of the same diameter, requires expensive forming tools.

The equipment by its very nature is not at all suited to avoid scufiing and abrading metal surfaces, as Well as the decorative colors, and lithography decoration and organic coatings when these are applied to the strip before the tube forming operation. Unscuffed pristine exterior decorative colors, lithographed decorations and coatings are necessary for retail customer acceptance. Furthermore, they are a requirement for such legal considerations as declared ingredients and declared weight. However, even more important is the fact that scratch free pristine interior coatings are vitally necessary to suitable container performance for the product contained therein because metal containers have the thinnest practical tin coating, and When possible no tin coating at all, in order to effect maximum economies. Thus, shelf life is dependent on the integrity of interior and exterior coatings and decorations. In addition to the aforesaid scuffing and scratching, such aforesaid welded pipe and heavy gauge tubing manufacturing equipment is not at all suitable for urging into tubular shape prescored thin strip of the gauges used for container manufacture. This unsuita-bility is due both to the fragility of the light gauge material and to the premature tearing which will occur along the transverse score prior to joining together the edges of such prescored thin strip. Thus, the unsuitability of the customary equipment is heightened when the metal surfaces of the tubing, both exterior and interior, as well as all decorations and organic coatings applied thereto, must be scuff and scratch-free.

Thus, it is a principal object of the invention to guide substantially continuously extending light gauge metal strips toward tubular configuration for an effective cooperation utilizing edge welded structures and processes of the prior art.

Another object of this invention is to provide an apparatus for forming a continuous tube from a thin metal strip for the later separation of the tube into container bodies wherein distortion is prevented so as to eliminate later distortion of the container bodies.

Another objectof this invention is to provide a suitable apparatus for guiding a thin metal strip into a tubular shape in a continuous operation without abrading and scufi'ing the surface of the strip wherein the strip may be suitably protectively coated or decorated prior to the shaping thereof and wherein the strip is suitable for the eventual forming of container bodies from the tube formed from the strip.

Another object of this invention is to provide an extremely simple apparatus for continuously shaping a metal strip into a tubular form, the apparatus being much less complex than that which is presently utilized in the forming of tubes and being of a nature to handle relatively thin metal.

A further object of this invention is to provide a novel apparatus for forming a continuous tube from an elongated strip, the apparatus including a plurality of roller assemblies wherein each roller assembly is formed of a plurality of rollers disposed about a circumferential path and the roller assemblies decreasing in radius from one end of the apparatus to the other whereby the transverse section of a strip moving therethrough is gradually changed from flat to substantially a complete circle.

Another object of this invention is to provide a novel roller assembly for use in the forming of a tube from a flat strip, the roller assembly including a plurality of rollers disposed in a circular pattern and including terminal rollers having lips for engaging edge portions of a strip so as to maintain alignment of the strip and prevent circumferential movement thereof.

Still another object of the invention is to provide a novel apparatus including roller assemblies as set forth above, wherein the strip is drawn through the roller assemblies by an apparatus which drives the resultant tube and thus tensions the strip.

A further object of this invention is to provide a novel apparatus in accordance with the foregoing wherein the rollers of the roller assemblies are drven in unison with the movement of the strip thereover.

A still further object of this invention is to provide a novel apparatus for forming on a continuous basis a tubular member from a flat strip, the apparatus including a plurality of raceways arranged to define a gradually increasing transversely curving surface, and the raceways having rolling elements therein for providing the necessary anti-friction support for the strip as it is being formed into a tube.

Still another object of this invention is to provide a novel apparatus in accordance with the foregoing wherein the raceways are continuous and there is a continuous circulation of the rolling elements.

With the above, and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

In the drawings:

FIGURE 1 is a partially sectioned, isometric view of an apparatus for continuously guiding a strip to a tubular shape in accordance with the invention.

FIGURE 2 and FIGURE 3 are transverse sectional views on an enlarged scale through the strip guiding structure shown in FIGURE 1 and taken along the lines 22 and 33, respectively, of FIGURE 1.

FIGURE 4 is a partially sectioned, isometric view of yet another apparatus for continuously guiding a strip to a tubular form in accordance with the invention, and illustrates still further features of the invention.

FIGURE 5 is a transverse sectional view of the structure shown in FIGURE 4, the view being on a large scale and being taken along the line 55 of FIGURE 4.

FIGURE 6 is a side elevational view of yet another apparatus for continuously guiding a strip to a tubular shape in accordance with the invention, and illustrates still further features of the invention.

FIGURE 7 and FIGURE 8 are fragmentary transverse sectional views on an enlarged scale of the structure of FIGURE 6 along the lines 7-'7 and 88, respectively, of FIGURE 6.

Referring now to the drawings in detail and with particular reference to FIGURE 1, there is shown a metallic strip 11 in the course of being guided to tubular shape, in accordance with processes and apparatus of the invention, for the joining together of opposite edge portions 13 of this strip as by welding apparatus.

The illustrative welding apparatus, as shown, includes a conventional source of radio frequency energy 15 con nected in serial relation with the opposite strip edge portions 13 through a pair of strip contacting electrodes 17.

The strip 11 is transported longitudinally from left to right, as shown, by means of a driven pair of flexible tensioning belts 19. The pair of belts I9 is driven through drive mechanism 21 and engage the exterior of a welded tube formed from the formed tubular strip 11. Although the drive mechanism 21 is shown at the illustrated ends of the belts, in practice the opposite ends of the belts would be driven to directly tension the belt runs engaging the welded tube T. Thus, this pair of belts 1% tensions the strip 11 for moving the strip from left to right for processing in accordance with the invention.

Both belts of the pair of belts 19 are driven simultaneously through the drive mechanism 21 by any convenient well-known power source, not shown here specifically. Such a power source may be, for example, an electrical drive motor (not shown) acting through the illustrated worm and gear drive arrangements 23. Thus, the pair of belts 19 exerts a continuing tensioning force on the strip 11 to transport this strip from left to right as shown.

The strip is initially flat and has transverse scorings 25. These scorings are spaced apart a distance commensurate with the length of the can body ultimately to be formed.

With particular advantage to the container manufacturing industry, the strip 11 may well consist of thin, tin plated steel of a thickness of the order of 0".004 inch to 0".011 inch. However, the invention is not restricted to the manufacture of containers or to tin plated steel.

The strip 11, being drawn by the tensioning apparatus, i.e., the pair of belts 19 with their associated drive mechanism 21, is transported from its left hand, flat configuration of FIGURE 1 through a plurality of guiding roller assemblies 31, 33, 35, 37 and 39. These roller assemblies are disposed transversely to the direction of movement of the strip and are arranged for exerting exterior guiding forces on the strip 11 in the course of transport of the strip. Each roller assembly, as will be described in more detail hereinafter, has a plurality of rollers disposed in circumferentially spaced relation and the rollers are spaced equidistant from a common center. The roller assemblies from left to right as shown, have decreasing transverse radii of curvature in correspondence with the longitudinal motion of the tensioned strip 11. Thus, the interior portions of the rollers in guiding contact with the strip define a curvilinear surface. This surface has an ever decreaasing transverse radius of curvature in correspondence with the longitudinal movement of the strip.

As the strip 11 is drawn from left to right, central portions thereof are urged downwardly against the roller assemblies, as is shown in FIGURE 1, by a roller member 27. The roller member is mounted for engaging the interior surface of the strip 11 centrally thereof and is mounted for free rotation in correspondence with the motion of the strip 11 following the tensioned urging of the pair of belts 19.

A momentary digression to consider the structures of FIGURE 2 and FIGURE 3 is desirable at this point. In the drawings the roller assemblies 33 and 39 are shown in elevation in guiding relation with the strip 11 which is shown in cross section. As is clearly shown in FIGURE 2, and FIGURE 3, the rollers of the roller assemblies are mounted for rotation about axes lying in planes disposed transverse to the direction of longitudinal motion of the strip 11. Thus, the roller member 27 urges the strip 11 downwardly against the guiding forces of the rollers of the roller assemblies 31, 33, 35, 37 and 39.

Passing from the influence of the downward urging of the roller member 27, the strip 11 passes under the influence of an interiorly disposed horn member 29. This horn member is held in position by a flanged support member 30 provided with suitable bolt holes for mounting on any convenient structure, not shown. Thus, as appears from that portion of FIGURE 1 wherein the tube T is broken away, the forming horn 29 opposes exterior urgings imposed on the strip 11 by the various successive ones of the plural roller assemblies.

Referring now to FIGURES 2 and 3 in particular, it will be seen that the roller assemblies 31, 33, 35, 37 and 39 are mounted on a common base B. Each roller assembly includes a pair of mounting plates 40 having notches 41 formed in the upper surface thereof in a circular pattern. In each of the notches 41, there is seated a roller 42. Each roller 42 is journalled for rotation on a shaft 43 with the plates 40 having the shaft 43 clamped therebetween. Each pair of plates 40 also carries a pair of terminal shafts 44 on which there are mounted for rotation terminal rollers 45 having lip portions 47 for engaging and retaining edge portions 13 of the strip 11. In this manner, the strip 11 not only has a transverse radius of curvature imparted thereto by the various roller assemblies, but also the strip 11 is retained against circumferential movement.

The roller member 27 acts downwardly against upwardly directed pressures exerted by the roller assemblies. By virtue of the decreased transverse radius of curvature of the rollers of the roller assemblies in the longitudinal passage of the strip 11 from the first roller assembly 31 to the last roller assembly 39, the strip is guided in its longitudinal passage, more and more toward a closed tubular configuration.

The edge portions 13 of the strip 11 are held apart in 6 spaced relation by a suitable spacer which may be the support member 30 associated with the forming horn 29. When the support member 30 functions as a spacer, it must be of an insulated construction to prevent current flow between the strip edge portions 13 therethrough. The strip edge portions come into contacting relation with the electrodes 17 downstream of the support member 30.

The still spaced apart strip edge portions in the course of their longitudinal travel now come under the influence of an assembly joining together rollers, generally referred to by the numeral 49 and best shown in FIGURE 1. Included in this assembly of rollers 49 are hour glass rollers 51, an exterior forging roller 53, an interior forging roller 55, an exterior support roller 57 and an interior support roller 59.

The hour glass rollers 51 serve to maintain opposite strip edge portions 13 in contacting overlapped relation. Thus, an electrically conductive current path is provided along the strip edge portions 13 from the generator 15 through the electrodes 17. In this manner heating cur rent from the electrodes 17 is allowed to fiow along the strip edge portions 13 to a point of mutual contact between the strip edge portions.

The interiorly and exteriorly disposed forging rollers 55 and 53 co-act with the now tubularly formed strip 11 to exert joining together pressures on the heated strip edge portions 13.

At the same time, the lower rollers 57 and 59 provide structural support for the horn 29 and thus the thin strip 11 to enable the forging pressures exerted by the upper forging rollers 53 and 55 to be effective.

It is readily apparent, too, that, in accordance with the invention, joining together apparatus, other than the forging together apparatus shown, may readily be employed in conjunction with the illustrated cooperative strip guiding structures. Thus, for example, adhesive materials rather than welding techniques may be employed for joining together strip edge portions.

Attention is directed next to FIGURE 4 wherein there is illustrated another embodiment of the invention. In FIGURE 4 apparatus similar to that of FIGURE 1 is shown and similar items having similar functions are identically numbered. For purposes of clarity and simplicity, the interiorly disposed forge roller 45 is not shown and the interior supporting connection of the forming horn 16 is not illustrated in this view.

Similarly, the base and supporting plates for rollers of the plurality of roller assemblies 31, 33, 35, 37 and 39 are not shown.

An important difference exists between the two structures of FIGURE 1 and FIGURE 4. In FIGURE 4 an electric drive motor 61 is shown as being belt connected with a longitudinally extending shaft 63 which, in turn, is suitably connected with the drive apparatus 21. The shaft is also connected to the plurality of roller assemblies. Hence, the rollers which constrain the strip 11 toward tubular configuration are connected for driving the strip in coherence with the tensioning exerted on the strip 11 by the belt members 19.

Thus, in this embodiment of the invention, the guiding to shape pressures are exerted transversely on the strip 11 by the several roller assemblies 31, 33, 35, 37 and 39 while at the same time, the coordinated driving of the rollers of these roller assemblies eliminates any tendency of the rollers to exert frictional abrading forces on the exterior surface of the strip 11.

A typical drive for the rollers of the several roller assemblies 31, 33, 35, 37 and 39 is shown in FIGURE 5. The roller assembly illustrated in this view is the roller assembly 33 and the support for the rollers is not shown. However, it will be seen that in lieu of mounting the rollers 42 and 45 on individual shafts, the rollers are all mounted on a single flexible shaft 65. The shaft 65 is suitably journalled in bearings 66 which are mounted in a manner not shown within the plates 49. Each of the 7 rollers 42 and 45 is rigidly secured to the flexible shaft 65 for rotation therewith.

The flexible shaft 65 is provided with a gear 67 which is meshed with a gear 69 carried by a transversely extending shaft 71. The shaft 71 is suitably journalled in a bearing 73 which is also mounted within the plates 40 in any desired manner.

Referring now to FIGURE 4 once again, it will be seen that the shaft 71 cooperates with the shaft 53 and is driven thereby. The shafts 71 and 63 are provided with mating gears of a gear assembly, generally referred to by the numeral 75. Although the drives for the roller assemblies 31, 35, 37 and 39 are only schematically illustrated, it is to be understood that they will be the same as that disclosed with respect to the roller assembly 33. It is also to be noted that the drive apparatus 21 is driven from the shaft 63 by means of a gear assembly, generally referred to by the numeral 77.

In this FIGURE 5, it is to be noted that the end rollers 55 of the transverse roller assembly 33 are shown more clearly in their relation with the guided strip 11. Here, these lipped end rollers 45 clearly restrain the strip 11 against transverse rotation as it is guided to shape under the upward constraints of the rollers 42 of the roller assembly 33 and of the downward urging of the roller member 27.

Turning next to FIGURE 6, there is seen yet another structure, in accordance with principles of the invention, for cooperation with joining together apparatus, for example, the welding apparatus illustrated in FIGURE 1 and FIGURE 4. The operation of the structure of FIGURE 6 may be more clear by first considering the section details illustrated in FIGURE 7.

In FIGURE 7 there are shown plural spherical roller members 101 arrayed transversely in contacting relationship with exterior portions of the strip 11. These roller members are retained in plural race members 105, having upper portions 107 and lower portions 109. The race members 105 are mounted on a base 111 by means of spaced brackets 113.

The upper portions 107 of the race members, as shown, are open for exposing the roller members variously arrayed within the race members interiorly of the race member array. This interior exposing of the roller members frees them for rolling contact with the strip 11. Thus, these exposed roller members are enabled to guide the strip to a desired configuration. This guiding is accomplished against internal restoring forces of the strip, and against the downward pressures exerted by the roller member 27 Turning next to FIGURE 8, there is seen another transverse section of the structure of FIGURE 6. This transverse section is taken in the later progress of the strip 11 in the strip process of being guided toward a closed configuration. Here the interiorly exposed spherical members 101 are arrayed transversely in contacting relation with the strip 11. This array is along a curve of radius decreased from the radius of curvature of the array illustrated in FIGURE 7. Similarly, the downward pressure on the strip exerted by the roll dr member 27, and the internal restoring forces of the strip, defines a curve of decreased radius shown in FIGURE 8 against which the roller members 101 may operate in transversely guiding the strip 11 towards the desired closed configuration.

Having considered these structural details of FIG- URE 7 and FIGURE 8, the overall guiding function of the plural roller members 101 arrayed within the race members 105 becomes more apparent in the structure of FIGURE 6 where the strip 11 is shown as it is tensioned for longitudinal motion from left to right This tensioning is accomplished, for example, by the structure of FIGURE 1. Thus, the strip 11 is urged to pass through plural spherical roller member arrays established by 8 plural roller members 101 disposed within the upper portions 107 of the race members 105.

The upper and lower portions 107 and 109 of the race members are connected, as shown, at opposite end portions of the race members. Thus, the contained spherical roller members are free to re-circulate in looped fashion through the race members. Hence, these spherical roller members 101 pass through the upper race member portions 109 from right to left in correspondence with longitudinal left to right motion of the strip, as shown. Since the race members are constructed, as seen in FIGURE 7 and FIGURE 8 for exposing inner roller portions, the rollers themselves are constrained to longitudinal guiding motion within the race members. This longitudinal motion follows the strip motion. Accordingly, frictional strip deformation is avoided.

At the same time, the race member configurations force the roller members to guide the strip transversely to a closed configuration. Thus, any tendency towards disfiguring of the strip exterior surface by frictional contact with the guiding spherical roller members is countered. This countering follows immediately from the fact that the spherical roller members move freely Within the race members albeit they exert transverse guiding forces on the strip which they contact.

For simplicity of description and since the positions of the roller members 101 are constantly changing as opposed to the fixed positions of the roller members 42 and 45, the rollers at any transverse point along the path of strip movement may be considered a group of roller members.

There have been illustrated three embodiments of principles of the invention. It will be apparent to those skilled in the art that many and varied departures from these illustrative structures may be made without departing from the spirit and scope of the invention, as defined in the appended claims. Thus, by way of typical example, it will be clear that strip edge portions may be joined together in accordance with the invention, as by gluing or by stapling. It will be similarly clear that the metal strip structures illustrated may readily be replaced by plastic or similar flexible strip members.

What is claimed as new is:

1. Apparatus for forming a thin substantially continuous strip of material, into a closed tubular configuration comprising, tensioning means exteriorly engaging said strip after forming for continuously transporting said strip longitudinally, groups of roller members spaced apart from said tensioning means in a direction opposite to that of the longitudinal motion imparted to the strip by said tensioning means, means for constraining the roller members of said plurality of roller member groups for rotation, said constraining means further comprising means for positioning the innermost peripheral surface portions of the roller members of said plurality of roller member groups to define a conical surface of transverse radius of curvature decreasing in radius in a direction towards said tenisoning means, and drive means for driv ing said roller members at the same peripheral speed as the effect of said tensioning means on the strip, said drive means including a plurality of flexible drive shafts each supporting all of the roller members of an associated one of said roller member groups and being drivingly C0n nected thereto.

2. Apparatus for forming a thin substantially continuous strip of material having a fixed Width into a closed tubular configuration, said apparatus comprising a plurality of groups of roller members spaced longitudinally of the path of movement of the strip, means mounting the roller members of each group for rotation about fixed axes with the axes of each group lying in a plane disposed normal to the path of movement, innermost peripheral surface portions of said roller members defining a conical surface of transverse radius of curvature decreasing in radius in the direction of strip movement,

9 10 all of the roller members of each group being mounted 2,551,704 5/1951 Radaelli 113-33 on a single flexible shaft for rotation therewith, and 3,001,569 9/1961 Gr-adt l13-33 means for rotating said flexible shafts in unison. 3,072,770 1/1963 Goodridge 2l959 References Cited by the Examiner 5 FOREIGN PATENTS UNITED STATES PATENTS 589,980 1/1960 Canada. 603 502 8/ 1960 Canada. 1,920,900 8/1933 Sykes 219-67 1,980,380 7/1934 Adam-s =113 33 ggg 10/119957 Germany- 2,007,284 7/1935 Rafter 153 -s4 10 0f 58 Japan- 2,098,989 11/1937 Yoder 153-54 2177104 10/1939 Gonser CHARLES W. LANHAM, Prlmary Exammer. 

1. APPARATUS FOR FORMING A THIN SUBSTANTIALLY CONTINUOUS STRIP OF MATERIAL, INTO A CLOSED TUBULAR CONFIGURATION COMPRISING, TENSIONING MEANS EXTERIORLY ENGAGING SAID STRIP AFTER FORMING FOR CONTINUOUSLY TRANSPORTING SAID STRIP LONGITUDINALLY, GROUPS OF ROLLER MEMBERS SPACED APART FROM SAID TENSIONING MEANS IN A DIRECTION OPPOSITE TO THAT OF THE LONGITUDINAL MOTION IMPARTED TO THE STRIP BY SAID TENSIONING MEANS, MEANS FOR CONSTRAINING THE ROLLER MEMBERS OF SAID PLURAITY OF ROLLER MEMBER GROUPS FOR ROTATION, SAID CONSTRAINING MEANS FURTHER COMPRISING MEANS FOR POSITIONING THE INNERMOST PERIPHERAL SURFACE PORTIONS OF THE ROLLER MEMBER OF SAID PLURLAITY OF ROLLER MEMBER GROUPS TO DEFINE A CONICAL SURFACE OF TRANSVERSE RADIUS OF CURVATURE DECREASING IN RADIUS IN A DIRECTION TOWARDS SAID TENSIONING MEANS, AND DRIVE MEANS FOR DRIVING SAID ROLLR MEMBERS AT THE SAME PERIPHERAL SPEED AS THE EFFECT OF SAID TENSIONING MEANS ON THE STRIP, SAID DRIVE MEANS INCLUDING A PLURALITY OF FLEXIBLE DRIVE SHAFTS EACH SUPPORTING ALL OF THE ROLLER MEMBERS OF AN ASSOCIATED ONE OF SAID ROLLER MEMBER GROUPS AND BEING DRIVINGLY CONNECTED THERETO. 